Hospital admissions resulting from preventable adverse drug reactions.

BACKGROUND: Adverse drug reactions (ADRs) are a significant cause of hospital admissions. These events can lead to significant morbidity and mortality and financial costs. ADRs that may be preventable might be considered a form of medication error.
OBJECTIVE: To assess the potential preventability of ADRs directly related to a patient's hospital admission.
METHODS: A retrospective chart review of 437 ADRs occurring during an 11-month period was conducted at a university hospital. A subset of these events leading to hospital admissions was identified for further review. Those that resulted in admission were further examined to determine probability of causality, severity, and preventability.
RESULTS: Over 11 months, 158 ADRs were directly related to hospital admission. The relationship of these admissions to drug exposure was determined to be probable or highly probable in 154 (97.4%) of these cases. From this group, 96 (62.3%) of these events were considered potentially preventable, with 23 (24%) considered severe to life-threatening. Characteristics associated with these ADRs included documentation of a toxic drug concentration or abnormal laboratory value (80%), inadequate monitoring of a patient's drug therapy (67%), inappropriate dose (51%), patient noncompliance (33%), drug-drug interaction (26%), contraindication to therapy (3%), and documented allergy (1%). These ADRs resulted in 595 hospital days, with an average length of stay of 6.1 days.
CONCLUSIONS: ADRs leading to hospital admissions are often preventable. Approximately 25% of these events were serious to life-threatening. Most resulted from inadequate monitoring of therapy or inappropriate dosing. Patient noncompliance and drug interactions were also common causes. Multidisciplinary prevention strategies among physicians, pharmacists, other healthcare professionals, and patients focusing on communication and education should be targeted.